#include <stdio.h>
#include <string.h>

char x[20][31000];
int len[31000], extra[20][20];
int dp[20][1 << 20], gone[20][1 << 20], fail[69000];
char X[69000];

void rec(int mask, int last) {
    int i, pmask = gone[last][mask];
    if (pmask == 0) {
        for (int i = 1; i <= len[last]; ++i)
            printf("%c", x[last][i]);
        return ;
    }
    for (i = 1; ; ++i)
        if (dp[i][pmask] + extra[i][last] == dp[last][mask])
            break;
    rec(pmask, i);
    for (int j = len[last] - extra[i][last] + 1; j <= len[last]; ++j)
        printf("%c", x[last][j]);
}

int main() {
    freopen("adn.in", "r", stdin);
    freopen("adn.out", "w", stdout);

    int N;
    scanf("%d\n", &N);
    for (int i = 1; i <= N; ++i) {
        gets(x[i] + 1);
        len[i] = strlen(x[i] + 1);
    }

    for (int i = 1; i <= N; ++i)
        for (int j = 1; j <= N; ++j) {
            int n = 0;
            for (int k = 1; k <= len[j]; ++k)
                X[++n] = x[j][k];
            X[++n] = '#';
            for (int k = 1; k <= len[i]; ++k)
                X[++n] = x[i][k];
            for (int k = 2; k <= n; ++k) {
                int pf = fail[k - 1];
                while (1) {
                    if (X[pf + 1] == X[k]) {
                        ++pf;
                        break;
                    }
                    if (pf == 0)
                        break;
                    pf = fail[pf];
                }
                fail[k] = pf;
            }
            extra[i][j] = 1 << 30;
            for (int k = len[j] + 2; k <= n; ++k)
                if (len[j] - fail[k] < extra[i][j])
                    extra[i][j] = len[j] - fail[k];
        }

    for (int i = 1; i <= N; ++i)
        for (int mask = 0; mask < (1 << N); ++mask)
            dp[i][mask] = 1 << 30;
    for (int i = 1; i <= N; ++i)
        dp[i][1 << (i - 1)] = len[i];

    for (int mask = 1; mask < (1 << N); ++mask)
        for (int i = 1; i <= N; ++i)
            if (dp[i][mask] != 1 << 30)
                for (int j = 1; j <= N; ++j)
                    if ((mask & (1 << (j - 1))) == 0)
                        if (dp[i][mask] + extra[i][j] < dp[j][mask ^ (1 << (j - 1))]) {
                            dp[j][mask ^ (1 << (j - 1))] = dp[i][mask] + extra[i][j];
                            gone[j][mask ^ (1 << (j - 1))] = mask;
                        }
    int go = 1;
    for (int i = 2; i <= N; ++i)
        if (dp[i][(1 << N) - 1] < dp[go][(1 << N) - 1])
            go = i;
    rec((1 << N) - 1, go);

    return 0;
}